.all{
    line-height: 30px;
    color: blue;
}

.mid{
    margin-top: 20px;
    margin-left: 10px;
}

table{
    border-collapse: collapse; // 单线变双线
}

table th, td{
    border: 1px solid royalblue;
    width: 120px;
    height: 30px;
    line-height: 30px;
    text-align: center;
}